Sulphur-containing esters



Patented Mar. 19, 1946 .sULPnUn-coNrAmme. nsrnas Henry D. Porter andArnold Weissberger, Rochester, N. Y., assignors to Eastman KodakCompany, Rochester, N. Y

Jersey No Drawing. Application Serial No. 588.0

a corporation of New April 12, 1945, cc

3 Claims. (01. 260-455 This invention relates to sulphur-containingesters, such as acylmercaptoalkanesulphonyl chlorides and to a processof making them.

In certain photographic systems such as'the" process described inPeterson U. S. patents,

2,296,306, granted September 22, 1942, and 2,353,754, granted July 18,1944, and Weissberger, Kibler and Young U. S. patent application, Ser.No. 539,780, filed June 10, 1944, it is desirable to use compounds whichcombine with other properties, the presence of a sulphonamido group andof a mercapto group. The mercapto group in turn should be protectedagainst oxidation during the synthesis of the com und, by an easilyhydrolyzable group, i. e., an acyl group.

The mercapto group serves to form silver salts as disclosed in thepatents and application above referred to, while the presence of thesulphonamido group increases the reactivity with solutes in processingsolutions, for example, with the oxidized developing agent used in theseprocesses. Color processes of the type above referred to use couplingcompounds containing a reactive methylene group or a phenolic hydroxylgroup which permits reaction of the coupler with the oxidized developerto form dyes in the photographic layer.

The presence of a sulphonamido group in these couplers improvesconsiderably the appearance of the resulting dyes. The presence of boththe mercapto group and the sulphonamido group is oi value in other caseswhere compounds are introduced in photographic emulsions in the form ofsalts with silver or with some other heavy metal.

Moreover, it is often desirable in the process referred to above tointroduce both critical groups with as little as possible increase inthe molecular weight of the compound. This restriction is desirable inthe color processes of this type in order that the coupler can beremoved after processing to avoid its adverse eflect on the finishedimage.

It is therefore an object of the present invention to provide a newcompound containing a potential mercapto group andcapable of producing asulphonamido group by reaction with a primary amino group in compoundscontaining active methylene or phenolic hydroxyl groups. A furtherobject is to provide a method for preparing such compounds.

These objects are accomplished according to our invention by thesynthesis of a new compound, p-acetylmercaptoethanesulphonyl chloride,CHaUOSCHzCHzSOaCl, which combines an 402m group and an SCOCHa group bymeans of two OH: groups. The S,O2Cl group serves to condense thecompounds with primary amines, thus forming the desired sulphonamidogroup SO2NH, and introducing at the same time SCOCHs, into the moleculewith the smallest practical increase in molecular weight. Other acylgroups, such as propionyl, might be used.

I The use, in the preparation of couplers, of acetyl thioglycolylchloride which combines an SCOCHs group with a carboxylic acid chloridegroup, is described in Weissberger, Kibler and Young U. S. patentapplication, Ser. No. 539,780. r

CHaCOSNa+BrCHzCHzSOaNa- CHaCOSCI-IaSOeNa-i-NaB The latter then isconverted to the corresponding sulphonyl chloride by reaction with aphosphorous halide, as follows:

. crncoscniornsoicwuaaroi The following example illustrates the method.

of preparing the compound:

To a hot solution of 1 equivalent of sodium fi-bromoethanesulphonate inethanol is added, all at once, a solution of 1.1 equivalents of sodiumthioacetate in 95% ethanol. After refluxingthe mixture for four hours,it is cooled and filtered to give a good yield of the sodiump-acetyl-mercaptoethanesulphonate. Recrystallization from 95% ethanolgives pearly flakes, M. P. 287-9? dec.

The powdered sodium p-acetylmercaptoethanesulphonate isstirred with anexcess by weight) of phosphorous oxychloride on the steambath for halfan hour. The excess phosphorous oxychloride is removed by' concentrationin vacuo, the residue slurried with carbon tetrachloride and the mixturestirred with ice water. After washing well with water the carbontetrachloride layer is dried, and concentrated in vacuo. A 40% yield ofp-acetylmercaptoethanesulphonyl chlorlde,'B. P. 65-'l0 at .2 mm., isobtained by distillation of the residue.

What we claim' is: 1. The compound p-acetylmercaptoethane- .sulphonylchloride.

2. The method of preparing p-acetylmercaptoethanesulphonyl chloride,which comprises refiuxing an alkali metal p-bromoethanesulphonate' withan alkali metal thioacetate to form an al- 1 kali metalp-acetylmercaptoethanesulphonate,

separating said last-mentioned compound by cooling the mixture, andreacting said last-mentioned compound with a chloride of phosphorus toform p-acetylmercaptoethanesulphonyl chlo- 3. The method of preparinfi-acetylmercaptoethanesulphonyl:chloride, which comprises refluxingsodium p-bnomoethanesulphonate with sodlum thioacetate to form sodiumB-acfitylmercaptoethanesulphonate, separating said. lastmentionedcompound by cooling the mixture, and reacting said last-mentionedcompound with phosphorus oxychloride to formp-acetylmercaptoethanesulphonyl chloride.

HENRY D. PORTER. ARNOLD WEISSBERGER.

